MISSION, Kan. (AP) — An inmate whose escape from a Kansas prison hidden in a dog crate became the subject of a book and TV movie has died behind bars.

John Manard, who was 45, died Sunday at the La Palma Correctional Facility, a private prison in Eloy, Arizona, according to the Kansas Department of Corrections. His cause of death is pending the result of an autopsy, department spokesperson Jennifer King said.

Manard was serving a life sentence for a suburban Kansas City killing at a prison in Lansing, Kansas, when he met Toby Young, a married mother of two who worked helping prisoners train animals for adoption. They struck up a romantic relationship.

On Feb. 12, 2006, Young, then 47, hid Manard, then 27, in a crate and helped him escape.

Prison officials said she took advantage of the trust she gained while running the program to drive Manard out of the prison. A guard who recognized Young did not thoroughly search the van.

Young and Manard were captured 12 days after the escape in east Tennessee on Interstate 75 between Knoxville and Chattanooga, about 90 miles (145 kilometers) south of a remote cabin they had been sharing.

Young, whose husband filed for divorce after her arrest, was sentenced in state court for her role in breaking Manard out. She also pleaded guilty in federal court to giving him a gun. She was freed in 2008 and wrote about what happened in the book, “Living With Conviction.”

“John is finally free. But I am crushed,” Young, who has since remarried and goes by Toby Dorr, said in a Facebook post Wednesday. “I pray you have at last found the peace you were searching for, John.”

The escape story also was featured on “Dateline” and is the inspiration behind the Lifetime movie, “Jailbreak Lovers.”

In a March 2006 letter to a Kansas City television station, Manard said he and Young “have a fairytale love the size of infinity.”